The Conservatives suffered a humiliating by-election defeat as the Liberal Democrats scored a historic win in Chesham and Amersham.

Lib Dem Sarah Green is the country’s newest MP after winning the formerly rock-solid Tory seat, which had been a Conservative stronghold since its creation in 1974.

Sir Ed Davey, the Lib Dem leader, said the result sent a “shockwave through British politics” by showing that the “Blue Wall” of Tory southern seats could be vulnerable.

The Tories sought to limit the damage, insisting it was difficult for governing parties to win by-elections, but defeated candidate Peter Fleet acknowledged the Conservatives had to rebuild “trust and understanding” with voters.

Conservative candidate Peter Fleet, who was defeated by Sarah Green of the Liberal Democrats, speaks to the media
Conservative candidate Peter Fleet, who was defeated by Sarah Green of the Liberal Democrats, speaks to the media

The contest was triggered by the death of former Cabinet minister Dame Cheryl Gillan, who took the seat with a majority of 16,233 in the 2019 general election – some 55 per cent of the vote.

Ms Green recorded 56.7 per cent of votes polled to secure a majority of 8,028.

“This Conservative Party has taken people across the country for granted for far too long,” she said.

"This campaign has shown that no matter where you live, or how supposedly safe a constituency may appear to be, if you want a Liberal Democrat member of Parliament, you can have a Liberal Democrat Member of Parliament.”

She added: “We will continue the work of holding this Government to account for letting Covid rip through the care homes.

"We will speak up for the three million people excluded from financial support throughout the pandemic and we will challenge Boris Johnson to be far more ambitious in tackling climate change, supporting our frontline workers and backing our small businesses.”

The scale of the defeat will ring alarm bells in Conservative Campaign Headquarters. Major issues in the campaign included the HS2 rail line, which cuts through the constituency, and the Government’s proposed planning reforms which have sparked fears about building in the countryside around the seat in the Chilterns.

Defeated Tory candidate Peter Fleet said: “Clearly this was a very disappointing result, not the result that I was expecting nor my team.”

He added: “It’s an absolutely extraordinary result which must take into account the fact that the Liberal Democrat party didn’t just throw the kitchen sink at this constituency, I think it was the microwave, the table, the oven, the dishwasher, the dog, the cat and anything else that was lying around as well.“